Android layout 在服务内部重复操作

从MainActivity我将意向传递给startService。该服务已成功启动

在该服务上，有一个小矩形文本（“hello，world”），它最初是在XML布局中初始化的。在下面复制的服务代码中，我首先将textView01文本改为表示日期和时间的字符串。这也是成功的（即，当服务启动时，用户从不会在屏幕上看到“hello，world”，只有日期和时间字符串）

在下面的代码中，我更新了延迟3秒的日期和时间。成功（我正在屏幕上实时查看字符串更改）

我的问题是：我无法让它不断重复更新。我试过了每一个循环，延迟，等待，睡眠，还有我研究过的所有我能想到的东西，都没有用。它当前只是在更新后停止——一次——3秒后

谢谢你能提供的任何帮助

package com.example.myapplication;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.graphics.PixelFormat;
import android.view.LayoutInflater;
import android.view.WindowManager;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.os.Handler;

public class FloatingWidgetShowService extends Service{
    WindowManager windowManager;
    View floatingView, collapsedView, expandedView;
    WindowManager.LayoutParams params ;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        floatingView = LayoutInflater.from(this).inflate(R.layout.floating_widget_layout, null);
        TextView innerView = floatingView.findViewById(R.id.textView01);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd G 'at' HH:mm:ss z");

        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_TOAST,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);

        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        windowManager.addView(floatingView, params);
        expandedView = floatingView.findViewById(R.id.Layout_Expended);
        collapsedView = floatingView.findViewById(R.id.Layout_Collapsed);
        floatingView.findViewById(R.id.Widget_Close_Icon).setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        stopSelf();
                    }
        });

        String currentDateandTime = sdf.format(new Date());
        innerView.setText(currentDateandTime);

        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                String currentDateandTime = sdf.format(new Date());
                innerView.setText(currentDateandTime);
            }
        }, 3000);

        expandedView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    collapsedView.setVisibility(View.VISIBLE);
                    expandedView.setVisibility(View.GONE);
                }
        });

        floatingView.findViewById(R.id.MainParentRelativeLayout).setOnTouchListener(new View.OnTouchListener() {
            int X_Axis, Y_Axis;
            float TouchX, TouchY;

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        X_Axis = params.x;
                        Y_Axis = params.y;
                        TouchX = event.getRawX();
                        TouchY = event.getRawY();
                        return true;
                    case MotionEvent.ACTION_UP:
                        collapsedView.setVisibility(View.GONE);
                        expandedView.setVisibility(View.VISIBLE);
                        return true;
                    case MotionEvent.ACTION_MOVE:
                        params.x = X_Axis + (int) (event.getRawX() - TouchX);
                        params.y = Y_Axis + (int) (event.getRawY() - TouchY);
                        windowManager.updateViewLayout(floatingView, params);
                        return true;
                }
                return false;
            }
        });
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (floatingView != null) windowManager.removeView(floatingView);
    }
}

---

只需将更新重新发布到

处理程序

，如下所示：

handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            String currentDateandTime = sdf.format(new Date());
            innerView.setText(currentDateandTime);
            // Now post the update to run again in 3 seconds
            handler.postDelayed(this, 3000);
        }
    }, 3000);